Treatments targeting the T cell receptor (TCR): effects of TCR peptide-specific T cells on activation, migration, and encephalitogenicity of myelin basic protein-specific T cells

Congruent Effects of Estrogen and T-Cell Receptor Peptide Therapy on Regulatory T Cells in EAE and MS

Both estrogen (E2) and T-cell receptor (TCR) peptides have beneficial effects on the clinical course of experimental autoimmune encephalomyelitis (EAE) and possibly multiple sclerosis (MS) that involve distinct but congruent mechanisms. Of interest, these two approaches share an ability to enhance expression of the FoxP3 gene and associated activity of regulatory T (Treg) cells. E2 increases the number and activity of FoxP3(+) T cells through Esr-1 signaling during TCR activation of CD4(+)CD25(-) T cells. In contrast, TCR peptide therapy appears to increase the frequency of regulatory FoxP3(+) T cells specific for self-TCR determinants expressed by targeted pathogenic T cells. The combined effects on Treg expansion and activation induced by these distinct immunoregulatory approaches may account for their potent effects on clinical EAE and argue for a similar combined therapeutic approach for MS.

Insights into the immunopathogenesis of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). Significant progress has been made in our understanding of the etiology of MS. MS is widely believed to be an autoimmune disease that results from aberrant immune responses to CNS antigens. T cells are considered to be crucial in orchestrating an immunopathological cascade that results in damage to the myelin sheath. This review summarizes the currently available data supporting the idea that myelin reactive T cells are actively involved in the immunopathogenesis of MS. Some of the therapeutic strategies for MS are discussed with a focus on immunotherapies that aim to specifically target the myelin reactive T cells.

Reduced chemokine and chemokine receptor expression in spinal cords of TCR BV8S2 transgenic mice protected against experimental autoimmune encephalomyelitis with BV8S2 protein

The perivascular transmigration and accumulation of macrophages and T lymphocytes in the CNS of mice with experimental autoimmune encephalomyelitis (EAE) may be partly regulated by low m.w. chemotactic cytokines. Using the RNase protection assay and ELISA, we quantified expression of chemokines and chemokine receptors in the spinal cord (SC), brain, and lymph nodes of BV8S2 transgenic mice that developed or were protected from EAE by vaccination with BV8S2 protein. In paralyzed control mice, the SC had increased cellular infiltration and strong expression of the chemokines RANTES, IFN-inducible 10-kDa protein, and monocyte chemoattractant protein-1 and the cognate chemokine receptors CCR1, CCR2, and CCR5, with lower expression of macrophage-inflammatory protein (MIP)-1alpha, MIP-1beta, and MIP-2; whereas brain had less infiltration and a lower expression of a different pattern of chemokines and receptors. In TCR-protected mice, there was a decrease in the number of inflammatory cells in both SC and brain. In SC, the reduced cellular infiltrate afforded by TCR vaccination was commensurate with profoundly reduced expression of chemokines and their cognate chemokine receptors. In brain, however, TCR vaccination did not produce significant changes in chemokine expression but resulted in an increased expression of CCR3 and CCR4 usually associated with Th2 cells. In contrast to CNS, lymph nodes of protected mice had a significant increase in expression of MIP-2 and MIP-1beta but no change in expression of chemokine receptors. These results demonstrate that TCR vaccination results in selective reduction of inflammatory chemokines and chemokine receptors in SC, the target organ most affected during EAE.